IGX

It is a given that American doctors perform a staggering number of tests and procedures, far more than in other industrialized nations, and far more than we used to. Since 1996, the percentage of doctor visits leading to at least five drugs' being prescribed has nearly tripled, and the number of M.R.I. scans quadrupled.

Certainly many procedures, tests and prescriptions are based on legitimate need. But many are not. In a recent anonymous survey, orthopedic surgeons said 24 percent of the tests they ordered were medically unnecessary. This kind of treatment is a form of defensive medicine, meant less to protect the patient than to protect the doctor or hospital against potential lawsuits.

Herein lies a stunning irony. Defensive medicine is rooted in the goal of avoiding mistakes. But each additional procedure or test, no matter how cautiously performed, injects a fresh possibility of error. CT and M.R.I. scans can lead to false positives and unnecessary operations, which carry the risk of complications like infections and bleeding. The more medications patients are prescribed, the more likely they are to accidentally overdose or suffer an allergic reaction. Even routine operations like gallbladder removals require anesthesia, which can increase the risk of heart attack and stroke.